Easy IMU ROS Package

This the ROS2 Package for the using the Easy IMU Module (MPU9250 EIMU Module) with ROS2 in a PC or microcomputer, after successful setup with the eimu_setup_application.

Note

It should be used with your ros2 project running on Ubuntu - ros-humble, ros-jazzy, etc.

How to Use the Package

• install the libserial-dev package on your linux machine

  sudo apt-get update
  sudo apt install libserial-dev

• install rosdep so you can install necessary ros related dependencies for the package (if you have not).

  sudo apt-get update
  sudo apt install python3-rosdep
  sudo rosdep init
  rosdep update

• cd into the src/ folder of your ros workspace and clone the repo

  git clone https://github.com/robocre8/eimu_ros.git

• from the src/ folder, cd into the root directory of your ros workspace and run rosdep to install all necessary ros dependencies

  cd ../
  rosdep install --from-paths src --ignore-src -r -y

• build the packages with colcon (in the root directory of your ros workspace):

  colcon build --packages-select eimu_ros --symlink-install

• before you start running the package, connect the Easy IMU Module to the Computer (PC or microcomputer) and check its serial port:

  The best way to select the right serial port (if you are using multiple serial devices) is to select by path

  ls /dev/serial/by-path

  You should see a value printed on the terminal (if the driver is connected and seen by the computer), your serial port would be -> /dev/serial/by-path/[value]. for more info visit this tutorial from ArticulatedRobotics

  • OR you can also try this:

  ls /dev/ttyU*

  you should see /dev/ttyUSB0 or /dev/ttyUSB1 and so on

• go to the config folder inside the eimu_ros package folder. You'll see two params file. Change the serial port value to that found in the previous step. You don't need to change the frame_id and publish_frequncy values. leave the publish_tf_on_map_frame value as it is in both param files.

• to vizualize in rviz (i.e quick test to see the IMU working), run:

  don't forget to source your ros workspace

  ros2 launch eimu_ros test.launch.py

  in another terminal run:

  rviz2

  Add TF and rotate the EIMU to see the transform from the imu frame to the map frame for test.

• to use in your project (e.g with a URDF file).

  Ensure the name of the imu link frame in your URDF FILE is the same as that of the frame_id in the eimu_ros_start_params.yaml

  First launch or run your robot's package file, then run:

  don't forget to source your ros workspace

  ros2 launch eimu_ros start.launch.py

  the imu data should now be published with (or on) the robot's imu link frame.

NOTE: Feel free to use/edit the package as you see fit on your project.

Sample robot test

• please chekout the easy_demo_bot package to see proper sample of how combine the EIMU with the EPMC and ekf sensor-fusion in a mobile robot.